The present application is a continuation-in-part application of my pending U.S. patent application filed Nov. 22, 1983, under Ser. No. 06/555,342 and now abandoned and having the same title.
The present invention pertains generally to face masks worn for the primary purpose of filtering out injurious matter such as pollen, dust, etc.
The prior art includes various types of face masks having an air filtering capability including masks having removable filters such as that mask disclosed in U.S. Pat. No. 2,845,926. The noted mask has a removable cellular element held in place between molded liner and outer mask members of generally triangular shape both of which define matching open areas for air passage. Removal of the filter insert from the mask incurs disassembly of the mask. Further, the semirigid molded plastic members of the mask do not conform to all facial contours resulting in gaps between face and mask, nor is a solid material next to the skin desirable from a comfort standpoint.
Other face masks primarily intended for filtration purposes include disposable masks having a cup-shaped member for placement over the nose and mouth. The cup-shaped member is of molded construction. Such disposable masks cannot be considered suitable for wear in a wide range of weather.
The present inventor has a copending patent application, filed Feb. 18, 1983 under Ser. No. 467,914 and now U.S. Pat. No. 4,520,509 which discloses a pliable outer member of a mask. U.S. Pat. Nos. 2,070,754 and 1,292,096 are of interest for they show removable air filters.